Scaffold structure



May 23, 1961 J. A. ISBELL SCAFFOLD STRUCTURE Filed Dec. 6, 1957 2 Sheets-Sheet 1 fizazzfar' May 23, 1961 J. A. ISBELL SCAFFOLD STRUCTURE 2 Sheets-Sheet 2 Filed Dec. 6, 1957 (/05 A. AFBELL KM flit United S ates Patent Q SCAFFOLD STRUCTURE Joe A. Isbell, Union City, Tenn., assignor, by direct and mesne assignments, to Union Metal Products, Inc., Memphis, Tenn., a corporation of Tennessee Filed Dec. 6, 1957, Ser. No. 701,258

4 Claims. (Cl. 254-135) The present invention relates broadly to scaffolding constructions, and is more particularly concerened with a new and improved readily assembled scaffold structure featuring speedy and reliable vertical adjustment of the work platform supported thereon.

During the course of utilization of scafiolding, it is of course frequently required that vertical adjustments be made in the height of the work platform inorder to present the workmen and materials supported thereon at a location convenient to the situs of Work. Vertically adjustable scaffolds of various types have been heretofore proposed; however, in the majority of instances the means employed were laborious to operate, limited considerably in the extent of vertical movement provided thereby, required the workmen to descend from the platform during both the raising and lowering operations, and the structure upon which said adjustment means were located were generally of fixed length and width.

It is accordingly an important aim of the present invention to provide a scaffold structure which avoids the deficiencies of prior art devices, and which includes means for effectively raising or lowering the work platform supported thereon without the necessity of the load carried by the platform being removed therefrom.

Another object of the invention lies in the provision of a vertically adjustable scaifold structure in which upward or downward movement of the work platform may be accomplished by a person on the platform with considerable ease and safety.

Another object of this invention is to provide a scaffold construction featuring novel means for raising or lowering the work platform carried on said scaffold, and additional means for individually adjusting the length of the vertical supporting members for the scaffold.

A further object of the present invention is to provide a scaffold structure which is of relatively light weight, may be readily assembled or disassembled, and may be easily transported from one location to another. I e

A still further object of the present invention .isto provide a novel scafiolding framework comprising vertie cal supporting members and horizontal bracing members extending theerbetween, and which additionally includes vertically movable members located between the supporting members for carrying the work platform, the vertical adjustment means for said movable members comprising a crank mechanism located above the movable members and having a cable or other suitable means attached to Patented May 23, 1961.

one of the vertically movable members and the bracketmeans therefor;

Figures 3 and 4 are horizontal sectional views taken substantially along the line III-III and IV-IV, respectively, of Figure 1;

Figure 5 is a view of the upper portion of the scaffold of this invention, and showing the stud portions upon which the crank mechanism subassembly is received;

Figure 6 is a detail view of the crank mechanism;

Figure 7 is a vertical sectional view taken substantially along the line VII-VII of Figure 6; and

Figure 8 is a vertical sectional view taken substantially along the line VIIIVIII of Figure 1.

Referring now to-the drawings, and particularly to Figure 1 thereof, applicants novel scaffold structure A comprises spaced uprights or vertical supporting members 10 under which are received plates 11. Each of the members 10 are of tubular construction and extending therebetween are a plurality of bracing members, the side braces provided along the longer dimension of the scaffold being designated by the numeral 12 and the relatively shorter end braces as 13. However, it will be appreciated that the scaffold could be square-shaped inplan or any other suitable configuration.

The braces 12 and 13 are each secured at their opposite ends to the vertical supports 10 by angle brackets 14 through which are passed bolts or the like 15 to establish a rigid connection with the supports 10, and yet per. mil: ready removal during disassembly prior. to movement to another site, or when it is desired to change the size of the scaffold A by utilization of shorter or longer braces- It. ispreferable in this instance that the braces be welded or otherwise secured to the angle brackets 14 through the use of joint blocks 16, and that the braces, brackets and blocks be removed as a unit by releasing the bolts, metal screws, pins or the like 15 whendisassembly is required for any purpose.

It may at times be found that the terrain upon which the scaffold is located is somewhat uneven, and means to compensate for this condition are herein provided. As shown in Figures 1 and 8, the tubular supports 10are free of attachment to the plates 11; however, located within each of the supports and suitably secured to said plates is an adjusting stud 17 provided with spaced holes 18 to correspond with holes 19 bored into one wall of the lower portion of the vertical supportsI A pin 20 or other device is received within thedesired holes in the stud and support, and to effect vertical adjustment of one or more of said supports to compensate for uneven ground and thereby assure a level condition of the work platform, the support 10 may be raised or lowered from the plate andthe pin 20 located in the proper aligned pairof holes 18 and 19. I k The horizontal" support for the work platform (not shown), and forming a part of the platform vertical adsaid mechanism and connected to said vertically movable jus'tm'ent mechanism of applicants inventio mis a pair of adjustable cross-beam supports 21 and 22 which preferably are of tubular construction and extend between the vertical support members 10 in vertically aligned parallel relation to the brace13. Carrying the adjustable sup ports 21 and 22 at each end thereof are brackets 23' of generally U-shape in cross-section as shown in Figures 2 and 3, each of said brackets having an integral shelf 7 portion 24 upon which the adjacent lower surface of each support rests. The ends of each support 21 and22 are preferably tightly received within the brackets 23, and removal is effected by raising the supports through the open top of each bracket. v

Each-bracket has welded, or in any other suitable man:

ner affixed to its end wall 25, an angle member or flange 26 having a hole 27 through one portion to receive ahook 28 provided for a purpose shortly to be described. The wall 25 of each support bracket 23 is offset outwardly along its lower edge as shown in Figure 2 to provide a portion normally received within the double head of a pin 29 passing through each vertical support during usage of the scaffold A. Pins 29 are inserted through the brackets and selected holes 30 in the. uprights, to support the brackets and crossbeams 21, 22 in desired vertical position. The function of the outwardly offset lower edge on the bracket, when located in the double head of the pin 29, is to prevent outward slippage of said pin from the hole 30 during use of the scalfold A.

Extending upwardly from within the upper portion of each vertical support 10 and rigid therewith is a stub 31, the upper end of which is received in a downwardly open pocket-like member 32 at the end of an elongated base beam 33 which carries a winch mechanism 34. Base beam 33 is an I-beam with upper and lower flanges 35, 36 and a vertical web 37. Sheaves 38 are journaled on the ends of beam 33. The beam, with its end members 32, winch mechanism 34, and sheaves 35, is readily lowered onto and lifted from stubs 31. When it is desired to operate the winch at a higher level, or at a lower level, the base beam and the parts carried thereby are readily removed and sections 10 are applied to or removed from the uprights and the base beam and the parts mounted thereon replaced.

As appears in Figures 1 and 6, the sheaves are mounted inwardly of the ends of the upper flange 35 of the. base, and trained thereover are cables 39 of proper strength characteristics. Outer ends of the cables have connected thereto the hooks 28 received in the holes 27 in the flanges 26, while the other ends of said cables are secured to the winch mechanism spool or drum 43.

The winch mechanism 34 is suitably affixed to the base 33 generally midway of the ends thereof and includes a substantially U-shaped supporting frame 40 having end walls 41 through which are passed a shaft 42 squared at opposite ends and supporting spool 43. A crank handle 44 is carried upon one end of the shaft, and the opposite end of the shaft is shaped to also receive the crank handle whereby the spool may be rotated from either end thereof.

Spaced substantially centrally of the spool length is ratchet wheel 45 integrally associated with said spool and having teeth 46 against which bear a pawl 47 pivoted on frame 40 by a shaft 49 and thrust toward the ratchet by a spring 48. Crank 51 on the ends of shaft 49 provide for releasing the pawl from the ratchet. Thus, while it is possible to raise the adjustable supports 21 and 22 and work platform carried thereby with a load upon said platform by turning of the crank handle, to release the pawl from the ratchet and to lower the platform first requires slight turning of the crank 44 to move the ratchet tooth away from the pawl, then rotating the pawl by its shaft 49 and crank 51 to completely disengage the pawl from the ratchet, then rotating the winch spool in the opposite direction by its crank 44. Raising and lowering of the platform may be accomplished with ease and safety by a person while supported on said platform.

It will now be apparent from the foregoing description that the scaffold of the present invention features ease and safety of operation, versatility permitting replacement of its various components with members of different sizes, and rapid assembly and disassembly when movement to another location is desired or a change in the height, width or length of the framework required. In the disassembly operation it is merely necessary to raise the crank mechanism base 33 upwardly from the stub portions 32, slide the adjustable supports 21 and 22 and brackets 23 upwardly from the vertical supports 10, release the bolts or other means from the braces 12 and 13, and raise the vertical supports 10 off the adjustable studs 17 attached to the plates 11. Assembly of the structure may also be speedily accomplished in generally the reverse order- As also appears from applicants disclosure, the assembled scaffold A shown in Figure 1 may be readily adjusted to compensate for uneven terrain by the novel adjustable stud arrangement described. In addition, vertical adjustment of the work platform carried upon the supports 21 and 22 may be effected without disassembly of the scaffold A, and particularly, requires only a small number of relatively simple steps on the part of the workman or other person. The crank mechanism subassembly operates with considerable reliability, and injury to personnel is rendered remote by the construction disclosed.

It is to be understood that the form of the invention herein shown and described is to be taken as the preferred embodiment of the same, and that various changes in the size, shape and arrangement of parts may be undertaken without departing from the spirit of the invention or the scope of the subjoined claims.

I claim as my invention:

1. A scaffold structure for supporting a work platform, comprising a plurality of uprights, side and end bracing members, secured at their opposite ends to spaced uprights, a lifting assembly comprising a rigid elongated base beam having downwardly opening pockets at its ends detachably mounted on and receiving the upper ends of two of said uprights, brackets slidable vertically on said two uprights below said beam, detachable elements securing said brackets to the uprights on which they are mounted, a platform carrying bar supported at its ends directly on said brackets, a cable winding device mounted on said beam between the ends of the latter, cables each secured at one end to said winding device and depending alongside of the uprights and secured at their other ends directly to said brackets.

2. An adjustable scaffold structure of the character described, which comprises spaced tubular vertical supports, removable bracing members extending therebetween, brackets of generally U-shaped horizontal cross section with their open sides facing laterally and directly applicable horizontally to the uprights and movable upwardly and downwardly thereon, detachable pins connecting the brackets to the uprights, a cross bar extending between said brackets and supported directly thereby, an upright stub telescopingly fitted to the upper end of each upright and supported thereby and projecting upwardly therefrom and having side faces flush with the side faces of the upright, a base beam having downwardly opening tubular pockets at its ends receiving the upper ends of said stubs, a rotatable spool mounted upon the base beam intermediate its ends, a crank therefor, and cables each attached at one end to the spool, the opposite ends of the cables being attached to individual ones of said brackets for raising or lowering the latter and the cross bar supported thereby upon rotation of the spool.

3. A scaifold structure for supporting a work platform, comprising a plurality of uprights, a transverse end brace secured at its opposite ends to two of said uprights, a platform-carryingcross bar extending between said two uprights and slidable vertically thereon, a rigid elongated base beam secured at its ends directly to said two uprights above said cross bar, winch spool and crank mechanism mounted on said base beam intermediate the ends thereof, and two cables each secured at one end to said spool and extending laterally therefrom toward an individual end of the base beam and then directly downwardly and secured at its other end directly to the corresponding end of said bar.

, 4. A scaffold structure for supporting a work platform, comprising a plurality of uprights, a transverse end brace secured at its opposite ends to two of said uprights, a platform-carrying cross bar extending between said two uprights and slidable vertically thereon, a rigid elongated base beam extending between said two uprights above said cross bar, means at the ends of said beam mounting the latter on said uprights and readily detachable therefrom, winch spool and crank mechanism mounted on said base beam intermediate the ends thereof, two cables each secured at one end to said spool and extending laterally therefrom toward an individual end of the base beam and then directly downwardly and secured at its other end directly to the corresponding end of said bar, said beam, winch spool and crank mechanism comprising a unit readily applicable to and removable from said two uprights by a workman standing on a platform carried by said cross bar.

6 References Cited in the file of this patent UNITED STATES PATENTS Strout Feb. 28, 1888 Gray Aug. 31, 1897 Hanlen Aug. 28, 1928 Pennington July 20, 1948 Landon Dec. 12, 1950 Cofling Nov. 4,, 1952, 

